Precipitate dissolution during deformation induced twin thickening in a CoNi-base superalloy subject to creep

The tensile creep performance of a polycrystalline Co/Ni-base superalloy with multimodal γ′ distribution has been examined at 800∘C and 300 MPa. rupture life the alloy is comparable to that RR1000 tested under similar conditions. Microstructural examination after testing revealed presence continuous precipitates M23C6 carbides along grain boundaries. Intragranularly, coarsening secondary occurred expense fine tertiary γ′. Long planar deformation bands, free γ′, were also observed traverse individual grains. Examination bands confirmed they microtwins. sections microtwins depleted stabilising elements across their entire width, suggesting certain compositions are susceptible precipitate dissolution during twin thickening. A mechanism for suggested based on Kolbe reordering mechanism.